Flashing light at night could help beat jet lag, Stanford study says

The body will eventually adjust to jet lag, it’s just that it takes time — about an hour a day to be precise. And anyone who has suffered the unpleasant side effects of jet lag – brain fog, body achiness, an overwhelming need for endless pots coffee — might have an interest in speeding the process up.

A new Stanford study suggests that exposing travelers to short bursts of flashing lights the night before a trip while asleep could help speed up the process significantly. In a press release I wrote on the study, which was published today in the Journal of Clinical Investigation, researchers explained how this works at a biological level:

The transfer of light through the eyes to the brain does more than provide sight; it also changes the biological clock. A person’s brain can be tricked into adjusting more quickly to disturbances in sleep cycles by increasing how long he or she is exposed to light prior to traveling to a new time zone.

Light therapy is designed to speed up the brain’s adjustment to time changes. By conducting light therapy at night, the brain’s biological clock gets tricked into adjusting to an awake cycle even when asleep. It’s a kind of “biological hacking” that fools the brain into thinking the day is longer while you get to sleep.

To determine whether continuous or flashing lights would provide the fastest method of sleep cycle adjustment, researchers had 39 study participants sleep in a lab, exposing some to continuous light for an hour, and others to flashing light for an hour. They found that the flashing light —which most could sleep through just fine— elicited about a two-hour delay in the onset of sleepiness, while those exposed to continuous light, the delay was only 36 minutes.

Jamie Zeitzer, PhD, the senior author of the study, described how flashing-light therapy could be used to adapt to traveling from California to the East Coast: “If you are flying to New York tomorrow, tonight you use the light therapy. If you normally wake up at 8 a.m., you set the flashing light to go off at 5 a.m. When you get to New York, your biological system is already in the process of shifting to East Coast time.”

“This could be a new way of adjusting much more quickly to time changes than other methods in use today,” he told me.